Fix the easy golint warnings

Reported by https://goreportcard.com/report/github.com/rfjakob/gocryptfs

internal/stupidgcm/stupidgcm.go

@@ -23,7 +23,7 @@ const (
 	tagLen = 16
 )
 
-// stupidGCM implements the cipher.AEAD interface
+// StupidGCM implements the cipher.AEAD interface
 type StupidGCM struct {
 	key         []byte
 	forceDecode bool
@@ -42,10 +42,12 @@ func New(keyIn []byte, forceDecode bool) cipher.AEAD {
 	return &StupidGCM{key: key, forceDecode: forceDecode}
 }
 
+// NonceSize returns the required size of the nonce / IV.
 func (g *StupidGCM) NonceSize() int {
 	return ivLen
 }
 
+// Overhead returns the number of bytes that are added for authentication.
 func (g *StupidGCM) Overhead() int {
 	return tagLen
 }

internal/syscallcompat/emulate.go

@@ -78,9 +78,8 @@ func emulateUnlinkat(dirfd int, path string, flags int) (err error) {
 	}
 	if (flags & unix.AT_REMOVEDIR) != 0 {
 		return syscall.Rmdir(path)
-	} else {
-		return syscall.Unlink(path)
 	}
+	return syscall.Unlink(path)
 }
 
 // emulateMknodat emulates the syscall for platforms that don't have it

mount.go

@@ -284,7 +284,7 @@ func initGoFuse(fs pathfs.FileSystem, args *argContainer) *fuse.Server {
 		// sync.Pool buffer pools are sized acc. to the default. Users may set
 		// the kernel constant higher, and Synology NAS kernels are known to
 		// have it >128kiB. We cannot handle more than 128kiB, so we tell
-		// the kernel to limit the size explicitely.
+		// the kernel to limit the size explicitly.
 		MaxWrite: fuse.MAX_KERNEL_WRITE,
 		Options:  []string{fmt.Sprintf("max_read=%d", fuse.MAX_KERNEL_WRITE)},
 	}

tests/test_helpers/helpers.go

@@ -422,8 +422,8 @@ func QueryCtlSock(t *testing.T, socketPath string, req ctlsock.RequestStruct) (r
 	return response
 }
 
-// Extract the exit code from an error value that was returned from
-// exec / cmd.Run()
+// ExtractCmdExitCode extracts the exit code from an error value that was
+// returned from exec / cmd.Run()
 func ExtractCmdExitCode(err error) int {
 	if err == nil {
 		return 0